Combining characters

[Doug Ewell]

Phil Smith III wrote:

> "newly needed letter-with-diacritic" -- does that happen? Venusian
> gets added and the ONLY issue is that it needs J+Combining Grave? I
> see the point but am not sure it's realistic,

This sort of thing is not uncommon with Native American orthographies (right here on Earth!) that are newly created, or for which Unicode encoding is new.

> and in any case isn't what I'm talking about: I'm asking about NEW
> combiners. Though "invalid" combinations can be an issue now, with
> different engines rendering them differently. At least if code comes
> across J+Combining Grave now, the combining-ness is known. When a
> Combining Backslash is added for Jovian, well, now that character is
> new and normalization adventures abound.

Normalization (NFC or NFD, not NFK*) for characters like this comes into play only when the character exists as both a precomposed unitary character and a combining sequence. When there is only one or the other, normalization to NFC or NFD yields the same result, and is thus a no-op, and not particularly adventurous.

> Actually they add a LOT of pain/complexity for certain use cases,
> because of normalization.

Only if a separate NFC (precomposed) or NFD (decomposed) form is added where one already exists, and IIRC there is indeed a policy against that.

--
Doug Ewell, CC, ALB | Lakewood, CO, US | ewellic.org